1.2 Provide redundant text links for each active region of a server-side image map.
Checkpoint
1.2 Provide redundant text links for each active region of a server-side image map.
Reading material
Notes: server-side image maps
An image map is a graphic on a web page with clickable 'hot spots'; clicking on a 'hot spot' takes the user to another web page.
It is not possible to add alternative text to each clickable area of a server-side image map, the solution is to provide an alternative set of text based links.
Server-side image maps are sometimes necessary, e.g. when the active regions of a client-side image map cannot be easily defined using an available geographic shape. When this is the case redundant text links should be provided.
Although client-side images are preferred over server-side image maps - as equivelent text can be provided for each image map 'hot-spot' - server-side image maps are sometimes necessary. For example, when the active regions of a client-side image map cannot be easily defined using an available geographic shape. In such cases the answer is to provide redundant text links relating to each link provided by the server side image map.
The following markup example is typical of the code used to reference a server side image map.
<a href="/cgi-bin/mymap.map">
<img ismap src="imagemap.gif" >
</a>
The web pages accessed by the clicking the image map in the above example would be completely hidden to someone using a screen reader or a text-only web browser, as there is no alternative way of accessing the links provided.
An example of the server side image with alt attribute added and an alternative set of links to the same content:
<a href="/cgi-bin/mymap.map">
<img ismap src="imagemap.gif"
alt="Alternative text links are provided at the foot of the page.">
</a>
The following links are made available at the foot of the page,
<p><a href="about.html">About Us</a> | <a href="research.html">Research</a> </p>
As you can see in the foregoing example, the alt attribute provided information about where to find the text based links. The alternative text based links imply that the image map has two hot-spots, one to find information about the organisation and another for information related to research.